Tuesday, 10 January 2017

What Climate Change Means for the Oceans

I’m going to warn you – the next few posts are likely to surround the topic of climate change, as a partial continuation of the previous one, but also because a pretty big topic has recently been brought to my attention, and I wanted to explore it a bit further. So, Part One of this “two-part series” will focus on how the oceans are being impacted by climate change.


Each year between 1970 and 2010, the temperature of the shallowest waters of the ocean increased by 0.1°C. This may not seem like a lot, until you look at that accumulatively. There’s 40 years recorded there, at 0.1°C per year, which is 4°C*. Again, 4°C likely doesn’t seem all that significant, but the reality is that this actually has quite negative implications for the aquatic life found within these waters, as well as the fact that overall wellbeing of the oceans themselves are highly compromised. How exactly? Well, in a number of ways – with some being more obvious than others, of course.

To start, there’s this whole thing around sea level rise. With mass ice melt happening around the world – particularly the frightening acceleration of the Greenland Ice Sheet finding its way into the ocean in liquid form – water levels are beginning to rise. This mostly impacts those living in coastal regions, such as my home province of Nova Scotia. But, as a bonus to these rising sea levels, the instances of drowning wetlands are also becoming a common occurrence. This means that coastal areas – wetlands – aren’t able to keep up with the rising water levels of the ocean, creating these neighbouring coastal areas to be submerged under water. Again, this is important because wetlands house a number of important species and ecosystems that are part of the already delicate balance of the natural world. So, seeing these two related impacts of climate change, happening before our eyes, is kind of important and alarming!

Okay, so you may be asking what’s the problem with a little extra water floating around? I’ll tell you what – it has a little something to do with a thing called the jet stream and ocean currents!

The currents that occur in the oceans are the result of a mixture of the earth’s latitudes** and varying water temperatures. What this means is that the warm air near the equator sucks in cooler air, which generates what is known as circulation cells. This is why it’s colder in the poles than at the equator. But, these circulation cells also bring about wind.

Wind is important for the movement and temperature control of the water. But, the warming of the oceans directly impacts the capacity of these wind patterns, which leads to the warming of the oceans’ waters, and as a result melts the ice that currently forms glaciers. And with this melt comes, the dilution of the ocean water, which leads to an inability for that cooler water to be pushed below, thus disabling the regulation process of ocean temperatures. This also leads to the creation of more extreme weather patterns***.

This destabilization of wind patterns also hinders the ocean currents from continuing another important function – providing nutrients to aquatic life particularly near the equator. If this provision of nutrients were to cease, well, say bye-bye to the ocean food chain, the many ecosystems within these vast areas of the planet, as well as an even more difficult process for the oceans to absorb carbon (this will be discussed in a second – stay with me!), leading to further – you guessed it – global warming!

In addition to these warming ocean temperatures is the occurrence of fish migration (which will somewhat be the basis of Part Two). Basically, as a result of the warming waters, fish species are beginning to migrate outside of their regular territories. In recent studies, there has been indisputable evidence to show that many fish species have been drawn towards the poles as a result of warmer water temperatures.

And finally, we should probably have a discussion about ocean acidification. One of the incredible functions of the oceans is its ability to absorb carbon dioxide – especially the nasty amounts we, human-folk, produce. It is believed the ocean can absorb around 30% of what we produce, although this has been challenged significantly in recent history, given the amounts created by humans each year. What does this mean? Well, the pH level of the ocean is beginning to drop, which has increased the acidity of the water.

Part of this acidification involves coral bleaching. The term coral bleaching refers to the physical colour transformation that takes place when the nutrients, and essentially, life of, coral ceases. We all associate coral, and more broadly coral reefs as being full of a variety of colours and movement. But, when coral dies, it turns a sedentary, white colour, devoid of life. The rise in water temperature has a major part in this transformation, as does pollution. And while this may not seem like a big deal, coral is an essential part of ocean wellbeing because it’s home to a lot of food sources not only for us humans, but a number forms of aquatic life.

Furthermore, this acidification leads to another complication for ocean wellbeing - the reduction of sulfur moving from the ocean into the atmosphere. The result of this inhibited process, is that it essentially prevents the reflection of solar radiation between earth and the atmosphere (and beyond), which is one of the ways this warming process we hear so much about takes place.   

But what does this all mean for those of us living outside of the oceans? Well, a lot, actually. When you think of just how significant the ocean is in terms of the make-up of the planet, we know it makes up approximately 70% of the earth’s surface. These oceans aren’t just there for us to access fish, or to enjoy a casual day out on the water – they actually directly impact climate and weather patterns, as was noted above. The scary bit about these impacts to climate and weather in the oceans, is that they also directly influence these same patterns in-land. Remember those droughts that seemed to affect most of the world this past summer? Don’t think this isn’t related to what’s happening in the oceans. The intensity of recent hurricanes, cyclones, and the lack of heavily dependent upon monsoons in several areas (such as parts of sub-Saharan Africa) are also a part of all this. They can impact everything from how food is produced (or not), to loss of coastal land, and even damage to homes and other livelihood-related impacts. So, to say what happens in the oceans stay in the oceans is on massive misunderstanding!

Lawrencetown Beach, Nova Scotia - aka one of my favourite places on earth
The realities of our changing climate can be found in all corners of the earth, if only we open our eyes wide enough to full accept what is happening around us. As someone who grew up near the Atlantic Ocean, maintain it as a multi-functioning ecosystem is something I need to pay more attention to. I also really hope to return home one day (and hopefully throughout the years to show it off too many friends made along the way) to eat all the fish in said ocean, so please, for my own selfish sake, keep my ocean happy and healthy!

-the Orange Canadian

*That 4°C, by the way, is equivalent to 7.2°F.
**Meaning, where in the world, latitudinally, these waters are located, as in the difference between the equator and the poles, and anywhere in between!
***Hellllloooooo Environmental History, circa 2011!

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